Work bench

[MY63]

Thanks @kgg it actually sounds very similar to my planned construction. With the exception of the horizontal studding which is not common here in the UK blown insulation of the type you describe is also uncommon. I plan to use solid insulation boards 4 in thick in the floor walls and roof. OSB 3 is indeed to be used as the vapour barrier on the warm side working outwards insulation followed by the breathable membrane then the 2 in air gap before the final sheeting.

All of the timber will be pressure treated and painted before construction begins as you can see from the drawing below there is a 12 sand and stone foundation to ground level then the complete box of 6 in concrete plinth to which the sole or sill plates will be attached complete with damp proof membrane. the floor joists will be hung from this plate, vents will also be fitted.

I am not an expert but have been fortunate to find a UK forum woodhaven2 where I obtained all of the information to build my workshop.

I have added another crude drawing below. 

 

2018-12-06_02-22-56 by my0771, on Flickr

I found some further information about working heights which suggested that for manual type working 6 in below shirt cuff height is best like woodworking and for more intricate work 6 inches above the cuff height is best so I may need one side higher and the other side lower or come up with a fantastic engineering solution to allow the bench heights to be changed.

 

[kgg]

Different continents and different climates have different construction needs. I am curious as to why you are going to paint the pressure treated timber the 2x4's and 2x6's which may in fact cause moisture to be retained in the timber. Over here the newer methods of pressure treatment of timber does not go to the core of the timber, just a mild penetration so the majority of the timber is still natural which will still have moisture. My thought process would be that painting the whole exterior of the timber you may prevent the core moisture from escaping and it would rot from within.

You also mentioned that you are planning on joist hanging the 2x 6 floor joists and the plans show their attachment to a 2x 4 bottom plate and the 4x6 sill plate. Why not just place 3/4" threaded bolts in the centre of the 12" x12" concrete foundation spaced every couple of feet when pouring and leave them protruding about 6" above the top of the concrete foundation. Then the next day when the concrete is solid enough install your damp proof membrane then bolt two 2"x6" on their flat all the way around on top of the concrete. Usually done so the second layer of 2"x6" joist plate overlaps the seams particularly in the corners left by the first layer of joist plate. The 2"x6" floor joists would then rest on the joist plates extending to the outside edge of the joist plate and then toe nailed to the double 2"x6" joist plate. This would be a lot less work, increase head room (very slightly) and provide a structurally stronger floor.

Then deck over and install the walls on top of the floor. Depending on the load of what you are putting in there you may need to go with a 12" joist spacing or larger joists. I am assuming you are planning on using 5/8" or 3/4" tongue and groove plywood decking / floor. Plywood would be stronger structurally, smoother surface and wear better. I would still consider putting down a vapour barrier over your sand and stone in the centre of your foundation to help prevent ground moisture from getting to the floor.

kgg

[Rustwa]

4 hours ago, MY63 said:

heights which suggested that for manual type working 6 in below shirt cuff height is best like woodworking and for more intricate work 6 inches above the cuff height is best so I may need one side higher and the other side lower or come up with a fantastic engineering solution to allow the bench heights to be changed.

I agree with that method of determining height. At my dayjob we have height adjustable tables with hydraulic jacks doing the work of adjusting. They are built like tanks with a meter by meter sized table weighing 1/3 of a ton. They are still not as sturdy as a fixed table weighing half that. I hope you do find a simple, easy, and effective way to make your table height adjustable and still be sturdy. A quick study of your layout leads me to think you won't be hindered by different heights in your workbenches. My old shop was laid out similar. I kept the tall bench clean and piled junk on the short one.